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Seismic PerformanceAssessment of BuildingsVolume 2 – Implementation Guide

FEMA P-58-2 / September 2012

FEMA


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FEMA P-58-2/ September 2012

Seismic Performance Assessment of Buildings

Volume 2 – Implementation Guide

Prepared by

APPLIED TECHNOLOGY COUNCIL201 Redwood Shores Parkway, Suite 240

Redwood City, California 94065www.ATCouncil.org

Prepared for

FEDERAL EMERGENCY MANAGEMENT AGENCYMichael Mahoney, Project Officer

Robert D. Hanson, Technical MonitorWashington, D.C.

ATC MANAGEMENT AND OVERSIGHT

Christopher Rojahn (Project Executive Director)Jon A. Heintz (Project Manager)Ayse Hortacsu

PROJECT MANAGEMENT COMMITTEERonald O. Hamburger (Project Technical Director)John GillengertenWilliam T. Holmes *Peter J. MayJack P. MoehleMaryann T. Phipps**

STEERING COMMITTEE

William T. Holmes (Chair)Roger D. BorcherdtAnne BostromBruce BurrKelly CobeenAnthony B. CourtTerry DooleyDan GramerMichael GriffinR. Jay LoveDavid MarSteven McCabeBrian J. Meacham

William J. Petak

* ex-officio ** ATC Board Contact

RISK MANAGEMENT PRODUCTS TEAM

John D. Hooper (Co-Team Leader)Craig D. Comartin (Co-Team Leader)Mary ComerioC. Allin CornellMahmoud HachemGee HeckscherJudith Mitrani-ReiserPeter MorrisFarzad NaeimKeith PorterHope Seligson

STRUCTURAL PERFORMANCE

PRODUCTS TEAMAndrew S. Whittaker (Team Leader)Gregory DeierleinJohn D. HooperYin-Nan HuangLaura Lowes

Nicolas LucoAndrew T. Merovich

NONSTRUCTURAL PERFORMANCEPRODUCTS TEAM

Robert E. Bachman (Team Leader)Philip J. Caldwell

Andre FiliatraultRobert P. KennedyHelmut KrawinklerManos MaragakisEduardo MirandaGilberto MosquedaKeith Porter

http://www.atcouncil.org/http://www.atcouncil.org/http://www.atcouncil.org/


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RISK MANAGEMENT PRODUCTSCONSULTANTS

Travis ChrupaloD. Jared DeBockArmen Der KiureghianScott Hagie

Curt HaseltonRussell LarsenJuan Murcia-DelsoScott ShellP. Benson ShingMohamed TalaatFarzin Zareian

STRUCTURAL PERFORMANCEPRODUCTS AND FRAGILITYDEVELOPMENT CONSULTANTS

Jack BakerDhiman Basu

Dan DolanCharles EkiertAndre FiliatraultAysegul GogusKerem GulecDawn LehmanJingjuan LiEric LumpkinJuan Murcia-DelsoHussein OkailCharles RoederP. Benson ShingChristopher Smith

Victor VictorssonJohn Wallace

NONSTRUCTURAL PERFORMANCEPRODUCTS AND FRAGILITYDEVELOPMENT CONSULTANTS

Richard BehrGreg HardyChristopher Higgins

Gayle JohnsonPaul KremerDave McCormickAli M. MemariWilliam O’BrienJohn OsteraasElizabeth PahlJohn StevensonXin Xu

FRAGILITY REVIEW PANELBruce EllingwoodRobert P. Kennedy

Stephen MahinVALIDATION/VERIFICATION TEAMCharles Scawthorn (Chair)Jack BakerDavid BonnevilleHope Seligson

SPECIAL REVIEWERSThalia AnagnosFouad M. Bendimerad

Notice

Any opinions, findings, conclusions, or recommendations expressed in this publication do not

necessarily reflect the views of the Applied Technology Council (ATC), the Department ofHomeland Security (DHS), or the Federal Emergency Management Agency (FEMA).

Additionally, neither ATC, DHS, FEMA, nor any of their employees, makes any warranty,expressed or implied, nor assumes any legal liability or responsibility for the accuracy,completeness, or usefulness of any information, product, or process included in this publication.Users of information from this publication assume all liability arising from such use.

Cover photograph – Collapsed building viewed through the archway of an adjacent building, 1999 Chi-Chi,

Taiwan earthquake (courtesy of Farzad Naeim, John A. Martin & Associates, Los Angeles, California).


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FEMA P-58-2 Preface iii

Preface

In 2001, the Applied Technology Council (ATC) was awarded the first in a

series of contracts with the Federal Emergency Management Agency

(FEMA) to develop Next-Generation Performance-Based Seismic Design

Guidelines for New and Existing Buildings. These projects would become

known as the ATC-58/ATC-58-1 Projects. The principal product under this

combined 10-year work effort was the development of a methodology for

seismic performance assessment of individual buildings that properly

accounts for uncertainty in our ability to accurately predict response, and

communicates performance in ways that better relate to the decision-making

needs of stakeholders.

This report, Seismic Performance Assessment of Buildings, Volume 2 –

Implementation Guide, is one in a series of volumes that together describe

the resulting methodology and its implementation. The procedures are

probabilistic, uncertainties are explicitly considered, and performance is

expressed as the probable consequences, in terms of human losses (deaths

and serious injuries), direct economic losses (building repair or replacement

costs), and indirect losses (repair time and unsafe placarding) resulting from

building damage due to earthquake shaking. The methodology is general

enough to be applied to any building type, regardless of age, construction or

occupancy; however, basic data on structural and nonstructural

damageability and consequence are necessary for its implementation.

To allow for practical implementation of the methodology, work included the

collection of fragility and consequence data for most common structural

systems and building occupancies, and the development of an electronic

Performance Assessment Calculation Tool (PACT) for performing the

probabilistic computations and accumulation of losses. The purpose of this

Volume 2 –Implementation Guide is to provide users with step-by-step

guidance in the development of basic building information, response

quantities, fragilities, and consequence data used as inputs to themethodology.

This work is the result of more than 130 consultants involved in the

development of the methodology and underlying procedures, collection of

available fragility data, estimation of consequences, development of

supporting electronic tools, implementation of quality assurance procedures,

and beta testing efforts. ATC is particularly indebted to the leadership of


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iv Preface FEMA P-58-2

Ron Hamburger, who served as Project Technical Director, John Hooper and

Craig Comartin, who served as Risk Management Products Team Leaders,

Andrew Whittaker, who served as Structural Performance Products Team

Leader, Bob Bachman, who served as Nonstructural Performance Products

Team Leader, and the members of the Project Management Committee,

including John Gillengerten, Bill Holmes, Peter May, Jack Moehle, and

Maryann Phipps. ATC is also indebted to Andy Merovich, Structural

Performance Products Team Member, for his lead role in the development of

this volume.

ATC would also like to thank the members of the Project Steering

Committee, the Risk Management Products Team, the Structural

Performance Products Team, the Nonstructural Performance Products Team,

the Fragility Review Panel, the Validation/Verification Team, and the many

consultants who assisted these teams. The names of individuals who served

on these groups, along with their affiliations, are provided in the list ofProject Participants at the end of this report.

ATC acknowledges the Pacific Earthquake Engineering Research Center

(PEER), and its framework for performance-based earthquake engineering,

as the technical basis underlying the methodology. In particular, the work of

Tony Yang, Jack Moehle, Craig Comartin, and Armen Der Kiureghian, in

developing and presenting the first practical application of the PEER

framework, is recognized as the basis of how computations are performed

and losses are accumulated in the methodology.

Special acknowledgment is extended to C. Allin Cornell and Helmut

Krawinkler for their formative work in contributing to risk assessment and

performance-based design methodologies, and to whom this work is

dedicated.

ATC also gratefully acknowledges Michael Mahoney (FEMA Project

Officer) and Robert Hanson (FEMA Technical Monitor) for their input and

guidance in the conduct of this work, Ayse Hortacsu for managing the

production of this report, and Bernadette Hadnagy, Peter N. Mork, and Laura

Samant for ATC report production services.

Jon A. Heintz Christopher Rojahn

ATC Director of Projects ATC Executive Director


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vi Table of Contents FEMA-P-58-2

2.5.12 Chilled Water and Steam Piping (D205 and D206) .. 2-392.5.13 Chillers, Cooling Towers, and Compressors

(D303) ........................................................................ 2-392.5.14 HVAC Distribution Systems (D304) ......................... 2-412.5.15 Packaged Air Handling Units (D305) ........................ 2-422.5.16 Control Panels (Table D306) ..................................... 2-43

2.5.17 Fire Protection (D401) ............................................... 2-432.5.18 Electrical Service and Distribution (D501) ............... 2-442.5.19 Other Electrical Systems (D509) ............................... 2-452.5.20 Equipment and Furnishings (E20) ............................. 2-452.5.21 Special Construction (F20) ........................................ 2-472.5.22 Nonstructural Performance Groups ........................... 2-47

2.6 Collapse Fragility Analysis ..................................................... 2-482.6.1 Nonlinear Response History Analysis ....................... 2-492.6.2 Simplified Nonlinear Analysis .................................. 2-492.6.3 Judgment-Based Approach ........................................ 2-542.6.4 Collapse Modes and PACT Input .............................. 2-56

2.7 Residual Drift Fragility ........................................................... 2-58

3. Building Analytical Model and Performance Assessments .......... 3-13.1 Introduction............................................................................... 3-13.2 Building Analytical Model ....................................................... 3-2

3.2.1 Nonlinear Response History Analysis ......................... 3-23.2.2 Simplified Analysis ..................................................... 3-33.2.3 Demand Directionality................................................. 3-4

3.3 Intensity-Based Assessment ..................................................... 3-43.3.1 Nonlinear Response History Analysis ......................... 3-43.3.2 Simplified Analysis ................................................... 3-113.3.3 Review Results .......................................................... 3-29

3.4 Scenario-Based Assessment ................................................... 3-343.4.1 Nonlinear Response History Analysis ....................... 3-35

3.4.2 Simplified Analysis ................................................... 3-403.4.3 Review Results .......................................................... 3-443.5 Time-Based Assessment ......................................................... 3-44

3.5.1 Nonlinear Response History Analysis ....................... 3-443.5.2 Simplified Analysis ................................................... 3-463.5.3 Review Results .......................................................... 3-54

4. Example Application: Intensity-Based Performance AssessmentUsing Simplified Analysis ................................................................ 4-1

4.1 Introduction............................................................................... 4-14.2 Obtain Site and Building Description ....................................... 4-1

4.3 Select Assessment Type and Performance Measure ................. 4-34.4 Assemble Building Performance Model ................................... 4-3

4.4.1 Project Information ...................................................... 4-34.4.2 Building Information ................................................... 4-44.4.3 Population Distribution ................................................ 4-54.4.4 Structural Components ................................................ 4-54.4.5 Nonstructural Components ........................................ 4-104.4.6 Collapse Fragility and Collapse Modes ..................... 4-164.4.7 Residual Drift Fragility .............................................. 4-19

4.5 Select Analysis Method and Construct Building Analytical

Model ...................................................................................... 4-19


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FEMA-P-58-2 Table of Contents vii

4.6 Define Earthquake Hazards .................................................... 4-194.7 Analyze Building Response ................................................... 4-24

4.7.1 Estimate Median Story Drift Ratio and Dispersion ... 4-244.7.2 Estimate Median Peak Floor Acceleration and

Dispersion .................................................................. 4-264.7.3 Estimate Median Residual Story Drift Ratio and

Dispersion .................................................................. 4-274.8 Input Response Data and Calculate Performance................... 4-284.9 Review Results ....................................................................... 4-29

5. Example Application: Time-Based Performance AssessmentUsing Nonlinear Response History Analysis .................................. 5-1

5.1 Introduction .............................................................................. 5-15.2 Obtain Site and Building Description....................................... 5-15.3 Select Assessment Type and Performance Measures ............... 5-2

5.4 Assemble Performance Assessment Model .............................. 5-25.5 Select Analysis Method and Construct Building Analytical

Model ....................................................................................... 5-3

5.6 Define Earthquake Hazards ...................................................... 5-35.7 Analyze Building Response ................................................... 5-10

5.8 Input Response Data and Calculate Performance................... 5-145.9 Review Results ....................................................................... 5-15

6. Structural Fragility Calculation ..................................................... 6-1

6.1 Introduction .............................................................................. 6-16.2 Building Description ................................................................ 6-1

6.3 Development of Structural Components and SystemFragilities by Calculation ......................................................... 6-56.3.1 Plywood Roof Diaphragm ........................................... 6-56.3.2 Tilt-Up Walls ............................................................. 6-136.3.3 Wall to Roof Attachments ......................................... 6-19

6.4 User-Defined Fragilities in PACT .......................................... 6-29

7. Nonstructural Fragility Calculation ............................................... 7-1

7.1 Introduction .............................................................................. 7-17.2 Unanchored Components ......................................................... 7-1

7.2.1 Overturning ................................................................. 7-27.2.2 Sliding Displacement .................................................. 7-6

7.3 Anchored Components ............................................................. 7-77.3.1 Code-Based Limit State Determination of

Anchorage Fragility ..................................................... 7-77.3.2 Strength-Based Limit State Approach to Anchorage

Fragility Calculation .................................................. 7-14

7.4 Displacement-Based Limit State Approach to DefineCalculated Fragilities .............................................................. 7-16

8. Consequence Function Development .............................................. 8-18.1 Introduction .............................................................................. 8-18.2 General Considerations ............................................................ 8-1

8.3 Calculation of Consequence Functions .................................... 8-28.3.1 Repair Cost .................................................................. 8-28.3.2 Repair Time ................................................................. 8-4


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viii Table of Contents FEMA-P-58-2

8.3.3 Unsafe Placards ........................................................... 8-58.3.4 Casualties ..................................................................... 8-7

8.4 Example Application ................................................................ 8-88.4.1 Estimation of Repair Cost ............................................ 8-88.4.2 Estimation of Repair Time ......................................... 8-10

8.5 Consequence Functions in PACT ........................................... 8-10

8.5.1 Provided Consequence Functions in PACT ............... 8-108.5.2 User-Defined Consequence Functions ...................... 8-108.5.3 Other Considerations ................................................. 8-14

Appendix A: Structural Component Fragility Specifications ............... A-1

Appendix B: Nonstructural Component Fragilities ............................... B-1

Appendix C: PACT User Manual ............................................................ C-1C.1 Introduction.............................................................................. C-1C.2 Hardware and Software Requirements .................................... C-1

C.3 Installing PACT ....................................................................... C-2C.4 PACT Control Panel ................................................................ C-2C.5 Model the Building and Import Analyses Results ................... C-3

C.5.1 Building Modeler Menus ............................................ C-4C.5.2 Project Information Tab .............................................. C-6C.5.3 Building Information Tab ........................................... C-6C.5.4 Population Tab ............................................................ C-7C.5.5 Component Fragilities Tab ......................................... C-9C.5.6 Performance Groups Tab .......................................... C-10C.5.7 Collapse Fragility Tab .............................................. C-11C.5.8 Structural Analysis Results Tab ................................ C-12C.5.9 Residual Drift Tab .................................................... C-14C.5.10 Hazard Curve Tab ..................................................... C-15C.5.11 Saving the PACT model ........................................... C-15

C.6 Evaluate Performance ............................................................ C-16C.6.1 Command Line Evaluation ....................................... C-18C.7 Examine Results .................................................................... C-18

C.7.1 Scenario/Intensity Results ........................................ C-19C.7.2 Time-Based Results .................................................. C-30

C.8 Fragility Specification Manager ............................................ C-33C.8.1 Overview Tab ........................................................... C-34C.8.2 Fragility Specification Details Tab ........................... C-35

C.9 Population Manager ............................................................... C-45C.10 Reporting ............................................................................... C-47C.11 A Look under the Hood ......................................................... C-48

C.11.1 Project Files .............................................................. C-48C.11.2 Results Files .............................................................. C-48

C.11.3 Fragility Specification Files ...................................... C-49C.11.4 Population Specification Files .................................. C-49C.11.5 Reporting Template Files ......................................... C-49C.11.6 Programming Notes .................................................. C-49

Appendix D: Normative Quantity Estimation Tool User Manual ........ D-1

D.1 Introduction.............................................................................. D-1D.2 Usage Notes ............................................................................. D-1D.3 Normative Quantity Estimate Tab ........................................... D-2


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FEMA P-58-2 List of Figures xi

List of Figures

Figure 1-1 Performance assessment process ....................................... 1-3

Figure 2-1 Format of PACT screenshots used, indicating the tab

title location ...................................................................... 2-1

Figure 2-2 PACT Project Information tab ........................................... 2-2

Figure 2-3 PACT Building Information tab ........................................ 2-3

Figure 2-4 Definition of floor and story numbers and floor andstory heights ....................................................................... 2-4

Figure 2-5 PACT Population tab showing commercial officeoccupancy .......................................................................... 2-9

Figure 2-6 PACT Population Manager utility ................................... 2-10

Figure 2-7 PACT Component Fragilities tab showing fragilityspecification selection ...................................................... 2-14

Figure 2-8 PACT Performance Groups tab. ...................................... 2-27

Figure 2-9 Normative Quantity Estimation Tool, Building

Definition Table. .............................................................. 2-48

Figure 2-10 Normative Quantity Estimation Tool, ComponentSummary Matrix. ............................................................. 2-48

Figure 2-11 SPO2IDA idealized pushover curve for hypotheticalstructure ........................................................................... 2-50

Figure 2-12 Plan of example structure................................................. 2-51

Figure 2-13 Section of example structure ............................................ 2-51

Figure 2-14 Pushover curve for 2-story reinforced masonry

building ............................................................................ 2-52

Figure 2-15 SPO2IDA Input ............................................................... 2-53

Figure 2-16 SPO2IDA Output ............................................................. 2-54

Figure 2-17 Comparison of collapse fragility functions obtained withtwo different approaches: SPO2IDA and Judgment. ....... 2-56


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xii List of Figures FEMA P-58-2

Figure 2-18 Illustration of multiple collapse modes ............................ 2-57

Figure 2-19 PACT Residual Drift tab .................................................. 2-59

Figure 3-1 Performance assessment procedure showing steps

covered in this chapter in shaded box. ............................... 3-1

Figure 3-2 Example spectra for scaled suite of 5 motions ................... 3-6

Figure 3-3 PACT Structural Analysis Results tab with responsehistory drift input.............................................................. 3-10

Figure 3-4 PACT Residual Drift input. .............................................. 3-10

Figure 3-5 Definition of floor, story numbers and floor heightsabove grade for two-story building .................................. 3-15

Figure 3-6 Lumped weight distribution ............................................. 3-15

Figure 3-7 Results from linear analysis ............................................. 3-16

Figure 3-8 PACT Structural Analysis Results tab, intensity-basedassessment ........................................................................ 3-27


Figure 3-10 PACT Control Panel ........................................................ 3-30

Figure 3-11 PACT Engine window ..................................................... 3-30

Figure 3-12 PACT Repair Cost tab ...................................................... 3-31

Figure 3-13 PACT Realizations tab ..................................................... 3-32

Figure 3-14 PACT Repair Cost tab showing repair cost by performance group ........................................................... 3-33

Figure 3-15 PACT Data Drill Down and Exports tab .......................... 3-34

Figure 3-16 Standard deviation of S a vs. T attenuation plot from

www.opensha.org ............................................................. 3-39

Figure 3-17 PACT Structural Analysis Results tab, scenario-basedassessment, nonlinear analysis ......................................... 3-40

Figure 3-18 Median S a vs. T attenuation plot from

www.opensha.org ............................................................. 3-42

Figure 3-19 PACT Structural Analysis Results tab, scenario-basedassessment, simplified analysis ........................................ 3-43

Figure 3-20 Seismic hazard plot showing segments ............................ 3-48

http://www.opensha.org/http://www.opensha.org/http://www.opensha.org/http://www.opensha.org/http://www.opensha.org/http://www.opensha.org/


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FEMA P-58-2 List of Figures xiii

Figure 3-21 Variation of mean annual frequency of exceedance for peak ground acceleration in g .......................................... 3-49

Figure 3-22 PACT Hazard Curve tab .................................................. 3-54

Figure 4-1 Plan view of example four-story office building ............... 4-2

Figure 4-2 Typical frame elevation for example four story office building .............................................................................. 4-2

Figure 4-3 PACT Project Information tab ........................................... 4-4

Figure 4-4 PACT Building Information tab ........................................ 4-5

Figure 4-5 PACT input screen for beam/column joint fragility .......... 4-6

Figure 4-6 Illustration of reinforced concrete element fragility

specification selections ...................................................... 4-7

Figure 4-7 PACT entries for 1st

floor structural performance groups,direction 1. ......................................................................... 4-9

Figure 4-8 PACT entries for 1st floor structural performance groups,

direction 2 ........................................................................ 4-10

Figure 4-9 PACT entries for 1st floor structural performance groups,nondirectional .................................................................. 4-10

Figure 4-10 Normative Quantity Estimation Tool, Building

Definition Table ............................................................... 4-11

Figure 4-11 Normative Quantity Estimation Tool, ComponentSummary Matrix showing nonstructural inventory ......... 4-11

Figure 4-12 PACT Performance Groups tab for floor 1,

non-directional. ................................................................ 4-13

Figure 4-13 Pushover curve developed by analysis ............................ 4-17

Figure 4-14 SPO2IDA Tool, SPO tab ................................................. 4-17

Figure 4-15 SPO2IDA Tool, IDA results tab ...................................... 4-18

Figure 4-16 PACT Collapse Fragility tab ............................................ 4-18

Figure 4-17 USGS hazard data for 1.0 second period atSite Class B ...................................................................... 4-21

Figure 4-18 Seismic hazard curve for S a(T = 1.13s), Site Class D ...... 4-22

Figure 4-19 USGS hazard data for peak ground acceleration ............. 4-23

Figure 4-20 Results from linear analysis. ............................................. 4.25


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xiv List of Figures FEMA P-58-2

Figure 4-21 PACT peak transient drift ratio input on StructuralAnalysis Results tab ......................................................... 4-28


Figure 4-23 PACT Repair Cost tab ...................................................... 4-30

Figure 4-24 PACT Repair Cost tab with realizations .......................... 4-31

Figure 5-1 Seismic Hazard Curve for Sa(T = 1.13s), Site Class D ...... 5-4

Figure 5-2 Segmented seismic hazard curve to be used for time- based assessment ................................................................ 5-5

Figure 5-3 Uniform Hazard Spectrum ................................................. 5-7

Figure 5-4 Deaggregation of segment 3 ............................................... 5-8

Figure 5-5 Conditional mean spectrum for segment 3 ......................... 5-8

Figure 5-6 PEER scaled record selection tool ..................................... 5-9

Figure 5-7 Selected records for segment 2 ......................................... 5-10

Figure 5-8 PACT Structural Analysis Results tab with drift inputfor intensity 3 ................................................................... 5-14

Figure 5-9 PACT Residual Drift tab input ......................................... 5-15

Figure 5-10 PACT Time Based Results tab showing annualizedrepair cost ......................................................................... 5-16

Figure 6-1 Roof plan ............................................................................ 6-2

Figure 6-2 Cross-sectional elevation.................................................... 6-2

Figure 6-3 In-plane attachment ............................................................ 6-4

Figure 6-4 Out-of-plane attachment ..................................................... 6-4

Figure 6-5 Horizontal holdown (out-of-plane) attachment .................. 6-4

Figure 6-6 Plywood diaphragm damage .............................................. 6-6

Figure 6-7 Plywood diaphragm damage .............................................. 6-6

Figure 6-8 Generalized force-deformation relationship adapted

from ASCE/SEI 41-06 ....................................................... 6-7

Figure 6-9 Determining plywood diaphragm damage states ............... 6-8

Figure 6-10 Fragility functions for plywood diaphragm in transversedirection............................................................................ 6-12


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FEMA P-58-2 List of Figures xv

Figure 6-11 Idealized moment-rotation relationship ........................... 6-14

Figure 6-12 Photo showing DS2 level cracking .................................. 6-16

Figure 6-13 Fragility functions for out-of-plane wall flexure ............. 6-19

Figure 6-14 Fragility function for in plane ledger to wallconnection ........................................................................ 6-22

Figure 6-15 Fragility function for out-of-plane wall-to-roofnailing .............................................................................. 6-28

Figure 6-16 PACT Fragility Specification Manager showing new

specification ..................................................................... 6-29

Figure 6-17 Fragility specification data input form ............................. 6-30

Figure 6-18 New fragility damage state definition form ..................... 6-31

Figure 7-1 Overturning parameters for unanchored objects ................ 7-2

Figure 7-2 Fragility function for overturning of 5-shelf metal bookcase............................................................................. 7-5

Figure 7-3 Fragility function for sliding of 5-shelf metal bookcase .... 7-7

Figure 7-4 Fragility function for anchorage of rigidly mounted

equipment designed under the 1994 UBC. ...................... 7-12

Figure 7-5 Fragility function for anchorage of vibration isolatedequipment designed under the 1994 UBC. ...................... 7-13

Figure 8-1 Initiating a new fragility specification in FragilitySpecification Manager ..................................................... 8-11

Figure 8-2 Add New Fragility window ............................................. 8-11

Figure 8-3 Consequence Function input window .............................. 8-12

Figure 8-4 PACT graph showing upper and lower bound repaircost data ........................................................................... 8-12

Figure 8-5 Other Consequences tab, Unsafe Placards input. ............. 8-13

Figure 8-6 Other Consequences tab, Casualty input. ........................ 8-14

Figure C-1 PACT shortcut icon. ..........................................................C-2

Figure C-2 PACT Control Panel ..........................................................C-3

Figure C-3 PACT Building Modeler window ......................................C-4

Figure C-4 File menu ...........................................................................C-4


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xvi List of Figures FEMA P-58-2

Figure C-5 Open File menu ................................................................. C-5

Figure C-6 Project Information tab with retrieved data fromopened file ......................................................................... C-5

Figure C-7 Edit, Tools, and Help menus ............................................. C-6

Figure C-8 Building Information tab ................................................... C-7

Figure C-9 Population tab .................................................................... C-8

Figure C-10 Population model data screens .......................................... C-9

Figure C-11 Component Fragilities tab ............................................... C-10

Figure C-12 Performance Groups tab .................................................. C-11

Figure C-13 Demand parameter selection data block .......................... C-11

Figure C-14 Collapse Fragility tab ...................................................... C-12

Figure C-15 Structural Analysis Results tab for entry of nonlinearanalysis results ................................................................ C-13

Figure C-16 Structural Analysis Results tab for entry of simplifiedanalysis results ................................................................ C-14

Figure C-17 Residual Drift tab ............................................................ C-15

Figure C-18 Hazard Curve tab............................................................. C-16

Figure C-19 PACT Engine window .................................................... C-16

Figure C-20 Analysis options menu .................................................... C-17

Figure C-21 PACT Engine progress screen......................................... C-17

Figure C-22 Results window ............................................................... C-19

Figure C-23 Performance Curve display options ................................ C-19

Figure C-24 Results displays ............................................................... C-20

Figure C-25 Changing performance grouping levels .......................... C-20

Figure C-26 Effects of changing performance grouping levels ........... C-21

Figure C-27 Repair Cost tab ................................................................ C-22

Figure C-28 Casualties tab .................................................................. C-23

Figure C-29 Repair strategy selection menu ....................................... C-24


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FEMA P-58-2 List of Figures xvii

Figure C-30 Repair time output assuming floors are repaired in parallel ............................................................................. C-25

Figure C-31 Repair time output assuming floors are repaired

sequentially ...................................................................... C-25

Figure C-32 Unsafe Placards tab .......................................................... C-26

Figure C-33 Realizations categories .................................................... C-26

Figure C-34 Individual Realization display of repair cost

contributions by performance group ................................ C-27

Figure C-35 Individual Realization display of repair timecontributions by performance group ................................ C-28

Figure C-36 Result Drill Down screen ................................................. C-29

Figure C-37 Screen showing options for exporting results .................. C-30

Figure C-38 Time-based results output screen ..................................... C-31

Figure C-39 Options menu showing base curve mode selection ......... C-31

Figure C-40 Options menu showing histogram bins option ................. C-31

Figure C-41 Average annualized loss output screen ............................ C-32

Figure C-42 Loss area charts buttons ................................................... C-32

Figure C-43 Loss Area Charts tab ........................................................ C-33

Figure C-44 File, Edit, and Tools menus ............................................. C-34

Figure C-45 Overview tab .................................................................... C-34

Figure C-46 Fragility Specification Details tab ................................... C-36

Figure C-47 Tree view showing: (a) sequential; and (b) simultaneousfragilities. ......................................................................... C-37

Figure C-48 Example complicated fragility structures consisting of

multiple sub-damage state groups and sub-sub-damagestate groups of several different types.. ...........................C-37

Figure C-49 Basic damage state level ..................................................C-37

Figure C-50 Consequence functions ....................................................C-38

Figure C-51 Adding damage state to different groups .........................C-38

Figure C-52 Combobox for selecting fragility type .............................C-38

Figure C-53 Creating mutually exclusive damage states. ....................C-38


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xviii List of Figures FEMA P-58-2

Figure C-54 General Info tab on Fragility Specification Detailsscreen............................................................................... C-39

Figure C-55 Create New Demand Parameter window ........................ C-39

Figure C-56 Notes tab on Fragility Specification Details screen. ....... C-40

Figure C-57 Damage State Group Type dropdown menu ................... C-41

Figure C-58 Damage State Group screen ............................................ C-41

Figure C-59 Fragility data display showing: (a) simultaneousdamage state group; and (b) mutually exclusive damage

state group ....................................................................... C-42

Figure C-60 Damage state information screen .................................... C-43

Figure C-61 Consequence Functions screen ........................................ C-43

Figure C-62 Repair Cost Consequence tab .......................................... C-44

Figure C-63 Repair Time Consequence tab......................................... C-44

Figure C-64 Other Consequence tab on Fragility SpecificationDetails screen .................................................................. C-45

Figure C-65 Building Population Manager window ........................... C-46

Figure C-66 Population model data screens ........................................ C-47

Figure C-67 Create Report window ..................................................... C-47


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FEMA P-58-2 List of Tables xix

List of Tables

Table 2-1 Height Factor Premium Values for Building Level ........... 2-6

Table 2-2 Occupancy Factors ............................................................. 2-8

Table 2-3 Fragility Groups in PACT ................................................ 2-12

Table 2-4 Fragility Classification for Reinforced Concrete

Moment Frames ............................................................... 2-19

Table 2-5 Fragility Classification for Low Aspect RatioReinforced Concrete Walls with Two Curtains of

Reinforcement .................................................................. 2-22

Table 2-6 Fragility Classification for Concrete Walls with Return

Flanges ............................................................................. 2-22

Table 2-7 Fragility Classification for Reinforced Masonry Walls ... 2-23

Table 2-8 Suggested Drift Accommodation Ratio δ a ....................... 2-28

Table 2-9 Tested Window Pane Sizes .............................................. 2-31

Table 3-1 Default Descriptions and Values for β c .............................. 3-9

Table 3-2 Default Descriptions and Values for β q.............................. 3-9

Table 3-3 Values of coefficient a ..................................................... 3-12

Table 3-4 Default Dispersions for Story Drift .................................. 3-18

Table 3-5 Default Dispersions for Peak Floor Accelerations ........... 3-21

Table 3-6 Default Dispersions for Total Peak Floor Velocity ......... 3-24

Table 3-7 Procedures for Estimating Median Story Ratio at Yield .. 3-25

Table 3-8 Drift Ratio Vectors ........................................................... 3-28

Table 3-9 Default Dispersions Ground Motion Variability, β gm ...... 3-38

Table 3-10 Segmented Seismic Hazard Values ................................. 3-49

Table 3-11 Segmented Peak Ground Acceleration Values ................ 3-50

Table 4-1 Fragility Group Selections for the Beam/ColumnComponents ....................................................................... 4-8


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xx List of Tables FEMA P-58-2

Table 4-2 Performance Group Quantities for Reinforced ConcreteElements ............................................................................. 4-9

Table 4-3 Performance Group Quantities for Plumbing

Components ...................................................................... 4-15

Table 4-4 Performance Group Quantities for Distributed HVACComponents ...................................................................... 4-15

Table 4-5 USGS Hazard Data, Adjusted for Building Period andSite Class .......................................................................... 4-22

Table 4-6 Lumped Weight Distribution ........................................... 4-24

Table 4-7 Median Story Drift Ratio Estimates ................................. 4-26

Table 4-8 Median Floor Acceleration Estimates .............................. 4-27

Table 5-1 Collapse Mode Consequences ............................................ 5-2

Table 5-2 Hazard Data, Adjusted for Building Period and SiteClass ................................................................................... 5-4

Table 5-3 Intensity Segment Values ................................................... 5-6

Table 5-4 Deaggregation Summary .................................................... 5-7

Table 5-5 Summary of Structural Analysis Results ......................... 5-11

Table 5-6 Residual Drift, Intensity 1 ................................................ 5-13

Table 5-7 Residual Drift, Intensity 3 ................................................ 5-13

Table 6-1 Basic Building Information ................................................ 6-2

Table 6-2 Damage State Descriptions for Plywood Roof

Diaphragm - Transverse ................................................... 6-12

Table 6-3 Damage State Descriptions for Tilt-Up Walls - Out-of-

Plane ................................................................................. 6-18

Table 6-4 Damage State Description for Ledger to Bolt Wall

Attachment – In-Plane ...................................................... 6-22

Table 6-5 Median In-Plane Limit State Strengths for AnchorBolt ................................................................................... 6-24

Table 6-6 Limit State Strengths Out-Of-Plane Attachment.............. 6-27

Table 6-7 Damage State Description for Wall Attachment (Purlin Nailing) – Out-of-Plane .................................................... 6-28

Table 7-1 Static Coefficient of Friction for Common SurfaceCombinations ..................................................................... 7-2


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FEMA P-58-2 List of Tables xxi

Table 7-2 Calculated Fragility Values for Metal Bookcases.............. 7-5

Table 7-3 Calculated Fragility Values for Filing Cabinets ................ 7-5

Table 7-4 Dynamic Coefficient of Friction for Common Surface

Combinations ..................................................................... 7-6

Table 7-5 Dispersion Values for Failure Mode 1 ............................. 7-15

Table 7-7 Suggested Drift Accommodation Ratios for Precast

Cladding and Other Brittle Cladding Systems ................. 7-16

Table 8-1 Repair Cost Estimate for Wall ........................................... 8-9

Table A-1 Structural Steel Elements (B103) ...................................... A-1

Table A-2 Reinforced Concrete Elements (B104) ............................. A-3

Table A-3 Masonry Vertical Elements (B105) .................................. A-6

Table A-4 Cold-Formed Steel Structural Elements (B106) ............... A-6

Table A-5 Wood Light Frame Structural Elements (B107) ............... A-6

Table B-1 Exterior Nonstructural Walls (B201) .................................B-1

Table B-2 Exterior Window Systems (B202) .....................................B-2

Table B-3 Roof Elements (B301, B303, B304) ..................................B-7

Table B-4 Partitions (C101) ................................................................B-7

Table B-5 Stairs (C201) ......................................................................B-8

Table B-6 Wall Finishes (C301) .........................................................B-9

Table B-7 Floor Finishes, Raised Access Floors, and Floor

Flooding (C302) ............................................................... B-10

Table B-8 Ceilings and Ceiling Lighting (C303) .............................. B-11

Table B-9 Elevators and Lifts (D101)............................................... B-12

Table B-10 Domestic Water Distribution (D202) ............................... B-12

Table B-11 Sanitary Waste Piping System (D203) ............................ B-13

Table B-12 Chilled Water Piping (D205) ........................................... B-13

Table B-13 Steam Piping (D206) ....................................................... B-14

Table B-14 Chillers, Cooling Towers, and Compressors (D303) ....... B-14

Table B-15 Distribution Systems (D304) ........................................... B-17

Table B-16 Packaged Air Handling Units (D305) .............................. B-18


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xxii List of Tables FEMA P-58-2

Table B-17 Control Panels and Instrumentation (D306) .................... B-18

Table B-18 Fire Protection (D401) .................................................... B-19

Table B-19 Electrical Service and Distribution (D501) ..................... B-20

Table B-20 Other Electrical Systems (D509) ..................................... B-22

Table B-21 Movable Furnishing (E202) ............................................ B-23

Table B-22 Special Structures (F101) ................................................ B-23

Table C-1 PACT Third Party Controls............................................. C-50

Table D-1 Summation Presentations in the Component Summary

Matrix ................................................................................ D-4


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FEMA P-58-2 1: Introduction 1-1

Chapter 1

Introduction

This report provides guidance on implementing the seismic performance

assessment methodology set forth in FEMA P-58-1, Seismic Performance

Assessment of Buildings, Volume 1 – Methodology, to assess the seismic

performance of individual buildings based on their unique site, structural,

nonstructural, and occupancy characteristics, expressed in terms of the

probability of incurring casualties, repair and replacement costs, repair time,

and unsafe placarding. This Implementation Guide contains examples

illustrating the performance assessment process, including selected

calculation and data generation procedures, as well user manuals for selectedelectronic materials provided in Volume 3 – Supporting Electronic Materials

and Background Documentation.

1.1 Purpose and Scope

The general methodology presented in Volume 1 can be applied to seismic

performance assessments of any building type, regardless of age,

construction or occupancy type. Many different means of implementing this

general methodology are possible. During the development of the general

methodology, the project development team found it necessary to develop a

tool to implement the methodology, which is provided in Volume 3 as the

Performance Assessment Calculation Tool (PACT). The problem

formulation and execution process outlined in this Implementation Guide is

sequenced to correspond to the input cues provided by PACT.

This Implementation Guide provides a detailed road map for users to follow

in applying the FEMA P-58 methodology to the unique site, structural,

nonstructural, and occupancy characteristics of their individual building to

obtain intensity-based, scenario-based, or time-based earthquake

performance assessments. Implementation requires basic data on the

vulnerability of structural and nonstructural components to damage(fragility), as well as estimates of potential casualties, repair costs, and repair

times (consequences) associated with this damage. This document also

provides examples for calculating user-defined structural and nonstructural

fragilities, and developing consequence functions.


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1-2 1: Introduction FEMA P-58-2

1.2 Limitations

This document tracks with the provisions of Volume 1, but does not

substantially duplicate its narratives, definitions, equations, and other

provisions. Readers are cautioned to use this document in conjunction with

Volume 1, and not to place complete reliance on Volume 2 alone forguidance on executing the methodology.

1.3 The Performance Assessment Process

Figure 1-1 illustrates the basic steps in the performance assessment process.

Volume 1 describes each of these steps and how they relate to the overall

performance assessment. Three of these steps, assembling building

performance model, defining earthquake hazards, and analyzing building

response, in addition to developing collapse fragility, when necessary, are

performed directly by the user. This Implementation Guide presents

illustrations of these steps with examples ranging from simple to more

complex.

Before starting the implementation, however, the user should select the

assessment type, performance measure, and analysis method that will provide

the desired output.

1.3.1 Assessment Types

Volume 1 defines three different seismic performance assessment types.

Each assessment type requires different input and utilizes different

procedures.

Intensity-based assessments evaluate a building’s probable performance

assuming that it is subjected to a specified earthquake shaking intensity.

Shaking intensity is defined by 5% damped, elastic acceleration response

spectra. This type of assessment can be used to assess a building’s

performance in the event of design earthquake shaking consistent with a

building code response spectrum, or to assess performance for shaking

intensity represented by any other response spectrum.

Scenario-based assessments evaluate a building’s probable performance

assuming that it is subjected to a specified earthquake scenario consisting ofa specific magnitude earthquake occurring at a specific location relative to

the building site. Scenario assessments may be useful for buildings located

close to one or more known active faults. This type of assessment can be

used to assess a building’s performance in the event of a historic earthquake

on these faults is repeated, or a future projected earthquake occurs.


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Time-based assessments evaluate a building’s probable performance over a

specified period of time (e.g., 1-year, 30-years, or 50-years) considering all

earthquakes that could occur in that time period, and the probability of

occurrence associated with each earthquake. Time-based assessments

consider uncertainty in the magnitude and location of future earthquakes as

well as the intensity of motion resulting from these earthquakes.

Figure 1-1 Performance assessment process.

1.3.2 Performance Measures

The seismic performance of a building is expressed as the probable damage

and resulting consequences of a building’s response to earthquake shaking.

The consequences, or impacts, resulting from earthquake damage considered

in this methodology are:

• Casualties. Loss of life or serious injury requiring hospitalization,

occurring within the building envelope.


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• Repair cost. The cost, in present dollars, necessary to restore a building

to its pre-earthquake condition, or in the case of total loss, to replace the

building with a new structure of similar construction.

• Repair time. The time necessary to repair a damaged building to its pre-

earthquake condition.

• Unsafe placarding. A post-earthquake inspection rating that deems a

building or portion of a building damaged to the point that entry, use, or

occupancy poses immediate risk to safety.

Each performance measure requires basic information about the building’s

characteristics.

1.3.3 Analysis Methods

The methodology provides users with a range of options for generating the

above assessments. Options include use of a simplified analytical estimationof building response or suites of detailed nonlinear response history analyses.

Building assets at risk can be defined by occupancy-dependent typical

(normative) quantities or building-specific surveys. The performance

characteristics of these at-risk assets can be represented by provided

relationships for component fragility and consequences, or component-

specific fragility and consequence functions can be developed and used.

Each building performance assessment can use either of the analysis

approaches or any combination of the options to define component fragility

and consequence characteristics.

The simplest application of the methodology includes use of the simplified

analysis method to estimate building response and the selection of provided,

occupancy-dependent fragility and consequence functions for the building

assets at risk. This streamlined approach may be most appropriate for

circumstances where information about building characteristics is limited, as

is typical during preliminary design of new buildings or in the initial

evaluation stages for existing buildings. In general, the more streamlined the

approach, the more limitations there are in the methodology’s ability to

characterize performance and the larger the inherent uncertainty in the

performance assessments.

1.4 Implementation Tools

Seven electronic products are provided in Volume 3 to help implement the

methodology. These are:

• Performance Assessment Calculation Tool (PACT). PACT is an

electronic calculation tool, and repository of fragility and consequence


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data, that performs the probabilistic calculations and accumulation of

losses described in the methodology. It includes a series of utilities used

to specify building properties and update or modify fragility and

consequence information in the referenced databases.

•

Fragility Database. The Fragility Database is an Excel workbook that isused to manage and maintain all provided fragility and consequence data

outside of PACT, and update database information within PACT.

• Fragility Specification. The Fragility Specification is a PDF file

displaying the contents of the fragility database. Each fragility

specification contains fragility and consequence data for the component

of interest, in a one-page format. Damage states are illustrated with

photos of representative damage, when available.

• Normative Quantity Estimation Tool . The Normative Quantity

Estimation Tool is an Excel workbook designed to assist in estimatingthe type and quantity of nonstructural components typically present in

buildings of a given occupancy and size.

• Consequence Estimation Tools. The Structural and Nonstructural

Consequence Estimation Tools are Excel workbooks that provide the

basis for provided consequence data, and can be used to assist in

estimating consequences for custom fragility specifications.

• Static Pushover to Incremental Dynamic Analysis (SPO2IDA).

SPO2IDA is an Excel workbook application that was originally

developed by Vamvatsikos and Cornell (2006). This tool uses empirical

relationships from a large database of incremental dynamic analysis

results to convert static pushover curves into probability distributions for

building collapse as function of ground shaking intensity.

• Collapse Fragility Tool . The Collapse Fragility Tool is an Excel

workbook application that fits a lognormal distribution to collapse

statistics obtained from a series of nonlinear dynamic analyses at

different ground motion intensity levels.

1.5 Organization and Content

This Implementation Guide is organized into the following chapters:

Chapter 2 provides a detailed description of the steps used to develop a

building performance model consisting of basic building information,

structural and nonstructural fragility specifications, consequence functions,

and the building’s collapse fragility and residual drift characteristics.


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Chapter 3 provides a detailed description of the steps required to execute

intensity, scenario, and time-based assessments.

Chapter 4 provides a step-by-step application of the methodology for an

intensity-based assessment that uses simplified analysis for estimating

building response and relies on provided fragility and consequence functionsto characterize component vulnerability.

Chapter 5 provides a step-by-step application of the methodology for a time-

based assessment that uses nonlinear response history analyses for estimating

building response.

Chapter 6 illustrates development of structural component fragility functions

by calculation to address unique circumstances or to supplement the provided

fragility functions.

Chapter 7 illustrates development of nonstructural component fragility

functions by calculation to address unique circumstances or to supplementthe provided fragility functions.

Chapter 8 provides guidance on the development of component consequence

functions to accompany user-defined fragility functions and to supplement or

modify provided consequence functions.

Appendix A lists structural components for which fragility and consequence

data are provided.

Appendix B lists nonstructural components and contents for which fragility

and consequence data are provided.

Appendix C provides instructions for the use of PACT.

Appendix D describes the Normative Quantity Estimation Tool that is

designed to assist in estimating the type and quantity of nonstructural

components typically present in buildings of a given occupancy and size.

A Glossary and list of Symbols, providing definitions of key terminology and

notation used in the methodology, along with a list of References, are

provided at the end of this report.


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FEMA P-58-2 2: Building Performance Model 2-1

Chapter 2

Building Performance Model

2.1 Introduction

This chapter provides guidance for assembling the building performance

model and is organized to provide direct references to the appropriate input

tabs the user will find in the Performance Assessment Calculation Tool

(PACT) provided in Volume 3. Figure 2-1 illustrates the format of PACT

screenshots provided throughout this document.

Figure 2-1 Format of PACT screenshots used, indicating the tab titlelocation.

The building performance model provides a systematic and quantitative

description of the building assets at risk of damage from earthquake ground

shaking effects. This model includes basic building characteristics (Section

2.2), an overview of fragility specifications and performance groups (Section

2.3), an organized description of the structural (Section 2.4) and

nonstructural (Section 2.5) components, the location of these assets withinthe building, an expression of their damageability and the consequences of

this damage, as well as a collapse fragility function (Section 2.6) expressing

the probability of building collapse, and a residual drift function (Section 2.7)

which is a measure of the building’s repairability.

2.2 Building Characteristics

2.2.1 Project Information

Assembly of the building performance model within PACT begins with the

Project Info tab, shown in Figure 2-2. This is used to input basic projectinformation used to identify the analysis files and results including Project

ID, Building Description, Client, and Engineer fields.


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2-2 2: Building Performance Model FEMA P-58-2

Figure 2-2 PACT Project Information tab.

PACT uses the Region Cost Multiplier and Date Cost Multiplier fields to

adjust provided component repair cost consequence functions to appropriate

present values. The provided consequence functions reflect repair costs

appropriate to Northern California in 2011. Users can address escalation and

regional cost variation through cost multiplier input using any suitable cost

index system. The cost modifier applies only to the cost data provided in the

PACT consequence function database. If the user provides building-specific

consequence cost data, these data should directly reflect the cost index

associated with the building’s locality and the assessment time, before

insertion into the performance model. If the user inputs independentlyderived consequence functions for all of the performance groups included in

the assessment, the region and date cost multipliers should be input as a

value of 1.0.

PACT uses the Solver Random Seed Value input to initiate all internally

programmed sequences of random number generation utilized in

performance assessment. If a Solver Random Seed Value of zero is used,

PACT will randomly seed each generation sequence. This will result in

different values for performance assessment results each time the same

problem is executed even if there are no changes to the input. While theresults of these assessments can be expected to be similar, users should input

a single digit non-zero integer to avoid seeing anomalous changes in

predicted performance when multiple evaluations of the same building are

performed. Note that if a sufficiently large number of realizations is used,

this effect is negligible.


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2.2.2 Building Information

Figure 2-3 illustrates the Building Info tab used to enter basic building data.

The red exclamation symbol, , appears whenever the value of an input is

outside a reasonable range, indicating a probable input error. This occurs for

many fields before data are entered, as a warning that entry is required.

Figure 2-3 PACT Building Information tab.

PACT uses the Number of Stories input as a basic index of the number of

demand parameters, performance groups, and calculations to be performed.

A story is defined as the building volume that extends from the top of slab or

other flooring at one floor level, to the top of slab or flooring at the nextlevel. It includes all things that are mounted on or above the lower floor and

which are present beneath the top of the higher level, such as the framing

supporting the higher floor or roof. The input value should include all stories

that have vulnerable components and which are to be included in the

performance assessment. If basements are present, and have vulnerable

structural or nonstructural components or occupants susceptible to injury,

these should be included as stories. Similarly, penthouses with vulnerable

components or occupants should be included as stories.

PACT defines the number of floors based on the Number of Stories input,where floor identifies all those components present within a story that are

located on top of the surface of the identified floor, and beneath the top

surface of the floor above. Thus, the first floor includes fragility groups for

framing that supports (and is beneath) the second floor; as well as

components that are supported on the first floor or suspended from the

second floor.


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Figure 2-4 illustrates the PACT definitions of floor and story numbers and

floor and story heights. Floor numbering should be initialized at the lowest

story housing damageable components. In the example of Figure 2-4, it has

been assumed that basement stories of this building do not contain

damageable components.

Figure 2-4 Definition of floor and story numbers and floor and story heights.

Core and Shell Replacement Cost should reflect a best estimate of the cost

to replace all building core and shell items, including an allowance for

building demolition and site clearance. Core and shell components include

the basic building structure and cladding and all nonstructural componentsthat are not typically provided by the tenants, such as elevators, stairs, toilet

rooms, and basic electrical and mechanical service. Total Replacement

Cost input includes the cost of core and shell constituents plus the cost to

replace tenant improvements and contents. Tenant improvements commonly

include office partitions, ceilings, light fixtures, HVAC, and electrical

distribution within occupied spaces except in common areas, such as lobbies

or central plants.

The Maximum Workers per Square Foot input is used to calculate repair

time. Values for this parameter should range from 0.0005 (one worker per

2,000 square feet) to 0.004 (1 worker per 250 square feet). During an actual

repair project there can be considerable fluctuation in the number of workers

per square foot of floor area. PACT provides a default setting of 0.001

which corresponds to one worker per 1000 square feet of floor area. Users

should generally execute their assessment with this default value, but can use

denser values when the building occupancy is such that owners will be

willing to bear the cost associated with more rapid repair schedules. Use of


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denser values will typically imply that the building will not be occupied

during repair, even if damage is not so great as to warrant this from other

perspectives. Users can perform multiple assessments using different values

of this parameter to understand how it affects the potential repair times.

The Total Loss Threshold is the ratio of repair cost to replacement cost atwhich a decision will likely be made to replace the building rather than repair

it. FEMA uses a value of 0.5 for this loss ratio when determining whether

post-earthquake repair should be funded. PACT uses a default value of 1.0

to maximize the amount of assessment information that will be obtained in

an assessment. Volume 1 suggests that when repair costs exceed 40% of

replacement costs, many owners will choose to demolish the existing

building and replace it with a new one.

The information placed in the Most Typical Default section is used to

populate a matrix of values for each floor, identified in the lower portion ofthe tab. Users can change the values in the matrix by entering other values

directly into the individual cells. Floor Area input is used to estimate the

number of casualties during an earthquake realization. Story Height is not

used within PACT, but input of a reasonable value is required.

In this matrix, the Height Factor is used to reflect increases in repair cost

attributable to:

• Loss of efficiency due to added travel time to get to damaged

components on upper levels

•

Material and tool loading and staging, including added cost for hoisting,

elevator loading, pumping, and disposal

• Access costs related to cutting openings or penetrations, removing

windows, loading and moving material to installation areas

• Scaffolding or rigging, including fall protection and protection to lower

areas

Minor cost adjustments may be appropriate for simple interior repairs, where

the impact is a minor loss of efficiency for worker elevator travel.

Significant adjustments may be necessary for exterior cladding repairs on ahigh-rise building which could require significant scaffolding for an

otherwise low cost repair item. Both of these extremes are unlikely to

produce a significant total repair cost error, since they are typically combined

with much less sensitive work items. While there can be a significant range

of height premium costs for individual items, the aggregated modifications


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will be a relatively small increase for most cases. Table 2-1 presents

suggested Height Factor premiums.

Table 2-1 Height Factor Premium Values for Building Level

Building Level Height Factor

Below grade levels and floors 1-4 1.00

Floors 5-10 1.08

Floor 11 and higher 1.16

The Hazmat Factor field is used to reflect the variable hazardous material

premiums. For new buildings, hazardous materials issues are generally a

function of occupancy. Healthcare and research facilities typically contain

some amount of hazardous material to support their operations. In many

older buildings hazardous materials have been removed as part of recent

tenant improvement and building modernization projects. Unless specific

information is known, a Hazmat Factor of 1.0 is recommended. It is

reasonable to expect this factor to range from 1.00 for modern buildings

without significant hazardous material content to 1.20 for buildings that

contain significant amounts of hazardous material including lead-based paint

and asbestos. Determination of Hazmat Factors should consider the

following:

• Friable asbestos insulation. This material is typically found in pipe

lagging in buildings constructed in 1979 or earlier. Friable lagging could

be present on all pipes in earlier construction. It was more commonly

applied only to boilers, bends and tees, and irregularly shaped elementsin later construction. While the cost for removal or abatement is high,

the extent is typically limited. A recommended mid-point range for

replacement or abatement is $10,000 per boiler or furnace, $50 per lineal

foot of piping, or alternatively $2 to $3 per square foot of overall gross

building area.

• Friable asbestos fireproofing. This material is typically found in

sprayed-on structural steel fireproofing in buildings constructed from the

1940s through the 1970s. Recommended midpoint cost for removal or

abatement is $20,000 per location of steel repair, $15 to $25 per square

foot of overall gross building area (based on 100% abatement).

• Non-friable asbestos cement products. These products are typically

found in flooring, siding or roofing of buildings but may be present in

limited quantities in fire protection. The cost of removal or abatement is

unlikely to be a significant factor in the repair costs for low to

moderately damaged buildings.


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• Asbestos containing materials. These materials are common in

buildings constructed from the 1940s through the 1970s and could be

present in earlier buildings. Asbestos containing materials are pervasive

and can be found in ceiling tiles, spray acoustic treatment, flooring

materials, floor mastic, roofing materials, caulk, and drywall taping

compound. A recommended cost for removal or abatement is

approximately $10 to $30 per square foot of overall gross building area.

• Polychlorinated biphenols. This material is commonly found in

electrical equipment that includes fluorescent light ballasts and caulk.

Polychlorinated biphenols (PCB) could be present in buildings

constructed before 1991, but are more likely present in construction

preceding 1980. In many cases, PCB ballasts have been replaced during

energy retrofits, so older buildings may not necessarily contain PCB

materials.

The following midpoint costs for removal or abatement are suggested:

o $100 per ballast for replacement in damaged fixtures. Ballasts in

undamaged fixtures should not need to be replaced following an

earthquake.

o Premium cost of $20,000 per item (in addition to equipment

replacement) of other electrical equipment (transformers,

switchgear).

o Caulk containing PCB has only recently been recognized as a

significant environmental problem. Repair protocols are not wellestablished. PCB can migrate from the caulk into surrounding

porous materials. This could necessitate not only caulk removal, but

also replacement of surrounding materials, such as masonry,

concrete, or wood. The midpoint costs suggested are for recaulking

only and for abatement or removal is $15 per lineal foot or $3 to $5

per square foot of overall gross building area.

• Lead based paint. In buildings constructed prior to 1980 painted

surfaces, particularly wood and steel, are likely to contain lead based

paint. Midpoint cost for removal or abatement is $3 per square foot of

painted area, or $2 to $5 per square foot for multi-unit residential and

education facilities, and $5 to $8 per square foot of overall building area

for complete structural steel abatement. For structural steel, $5,000 per

repair location may be used.

There are many other hazardous materials and conditions that could be

encountered in repair efforts. In the larger context of seismic repair,


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typically these treatments are inconsequential from a cost perspective. These

materials can include mercury in light fixtures and switching devices

(thermostats), dry-cleaning fluids, gasoline, diesel or other hydrocarbons in

generators or fuel storage tanks, chemicals from process or manufacturing,

and radioactive materials (particularly in healthcare or laboratory

equipment).

The Occupancy Factor reflects the added cost of working around ongoing

building operations, equipment, and the collateral protections required for

some construction characteristics. The repair premium is significantly more

pronounced in occupied buildings than in vacated buildings. However, the

level of collateral protection required even in an unoccupied building may be

significant. Table 2-2 lists recommended repair premiums for typical

occupied and unoccupied buildings. PACT does not presently distinguish

between occupied and unoccupied repair conditions.

Table 2-2 Occupancy Factors

Occupancy Category

Occupancy Factor

Unoccupied Occupied

Commercial Office 1.0 1.2

Research 1.4 1.8

Healthcare 1.5 2.0

Education K-12 1.0 1.1

Multi-Unit Residential 1.1 1.2

Retail 1.2 1.3Warehouse 1.1 1.1

Hospitality 1.1 1.3

For time-based assessments, “unoccupied” factors should be used. For

scenario- and intensity-based assessments, “occupied” factors should be used

for low intensity shaking since repair of minor damage is likely to be done

while the building is occupied. For moderate to high intensity shaking, the

use of the “unoccupied” factors is recommended, as buildings are more likely

to be damaged beyond a level at which repair during occupancy is practical.

2.2.3 Population Model

To assess casualties, users must define the population model, i.e., the

distribution of occupants within the building at various times of day. In

PACT, it is possible to use one of the provided building population models or

to develop and input building-specific models. Eight population models are

provided in PACT corresponding to typical commercial office, education K-


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12 (elementary, middle, high school), healthcare, hospitality, multi-unit

residential, research, retail, and warehouse occupancies.

Users can assign separate population models to several fractions of each floor

level. Each population model includes the hourly distribution of people per

1,000 square feet for weekdays or weekends and can be adjusted to includefurther variation by month. Provided population models can be used directly

or be modified to reflect the unique occupancy characteristics of a specific

building, if known. Figure 2-5 illustrates the commercial office occupancy

provided in PACT. Building-specific population information can be

developed and modified using the Population Manager utility, as illustrated

in Figure 2-6. The provided population models for each occupancy category

can be viewed by selecting from the column on the left and modified by

substituting data on the right side of the window. New occupancy models

can be created by overwriting the existing ones or creating new names for the

occupancy.

Figure 2-5 PACT Population tab showing commercial office occupancy.


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Figure 2-6 PACT Population Manager utility.

2.3 Fragility Specifications and Performance Groups

Following the definition of the general building characteristics, it is

necessary to define the quantity, vulnerability, and distribution of

damageable components and contents. PACT organizes this process into two

parts: (1) identification of required fragility specifications for each floor, and

(2) identification of the quantity of components in each performance group at

each floor.

The fragility specification includes a description of the demand parameter

that predicts damage, the types of damage that can occur, fragility functions,

which indicate the probability of incurring each damage state as a function of

demand, and consequence functions, which indicate the probable values of

loss that will occur as a result of each damage state.

Each fragility function specifies damage state probabilities for a single

demand parameter. Typically, peak story drift ratio or peak floor


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acceleration parameters are used to determine if a component is damaged.

The demand parameter can have a specific orientation with respect to the

component (directional demand) or the demand can be non-directional. For

example, wall elements will typically be damaged by story drift within their

plane, where suspended ceiling systems are susceptible to damage from floor

acceleration independent of horizontal direction. Users should be aware that

floor acceleration important to the damageability of a component, such as

ceiling mounted nonstructural components, may be associated with the floor

level above the level under consideration. Unanchored nonstructural

components use peak total floor velocity as the demand parameter.

User-defined, building-specific fragility functions can use any appropriate

demand parameter. For example, a user could decide that beam-column joint

plastic rotation is the best predictor of damage for a particular type of

structural component and could develop fragility functions based on that

parameter. If demand parameters other than story drift ratio, floor

acceleration, or velocity are used, the structural analysis used to estimate

building response must provide values for the selected demand parameters.

The quantity and distribution of damageable components conforming to each

selected fragility specification is entered into PACT through the definition of

performance groups at each floor level. A performance group is a set of

components described by a single fragility group that will experience the

same demand. Performance groups are ordered by the direction of

application of their common demand parameter.

In PACT, components can be selected and distributed across the building’s

floors to create a complete representation of the damageable building. To

determine the quantities of vulnerable nonstructural components and contents

within a building, the Normative Quantity Estimation Tool provided in

Volume 3 can be utilized.

Users should be aware that the list of component fragility specifications

provided with PACT does not include all vulnerable building components

that may be present in a building. Users must carefully identify damageable

building features not provided in PACT. User-defined fragility and

consequence functions can be developed following the guidance provided in

Chapters 6, 7, and 8.

2.3.1 Fragility Specifications Provided in PACT

PACT references a data set of more than 700 individual fragility

specifications, containing both structural and nonstructural components,

contained in the Fragility Database provided as part of Volume 3. Table 2-3

provides a list of fragility groups identified in PACT where fragility groups


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with fragility specifications provided in PACT are indicated with bold

lettering. Figure 2-7 illustrates the PACT window used to select fragility

groups present in a performance model.

Each fragility group is identified by a unique identification code based on

recommendations contained in NISTIR 6389 Report, UNIFORMAT II Elemental Classification for Building Specifications, Cost Estimating and

Cost Analysis (NIST, 1999), where codes take the form: A1234.567. The

first letter in the classification system indicates the overall component

category. The first two numbers provides the next categorization. For

instance, B10 represents superstructure components while B20 represents

exterior enclosures. The next two numbers identify a unique component.

For example, the classification for reinforced concrete shear walls is B1044.

The identifiers after the decimal provide variations of the basic component

and are used to identify different configurations, conditions of installation,

material quantities, demand levels, and other attributes.

Note that many building components are inherently rugged and not subject to

significant damage for credible levels of demand. Rugged components

include such things as plumbing fixtures, electrical raceways, wall-mounted

panels, and some components of gravity framing sy

Documents

FEMA-Volume2(1)